代码
<html xmlns="http://www.w3.org/1999/xhtml" >
<head runat="server">
<title></title>
</head>
<body>
<form id="form1" method="get">
<div>
<input type="image" src="but_seab.gif" value="测试坐标系" />
</div>
</form>
</body>
</html>
<head runat="server">
<title></title>
</head>
<body>
<form id="form1" method="get">
<div>
<input type="image" src="but_seab.gif" value="测试坐标系" />
</div>
</form>
</body>
</html>
当点击提交的图片按钮时会在出现两个参数x,y是鼠标在点击图片的时候图片的坐标值，解决方案是放弃用image控件，改为用submit或者Button，加个背景图片即可。
在w3.org上是这么解释的
When a pointing device is used to click on the image, the form is submitted and the click coordinates passed to the server. The x value is measured in pixels from the left of the image, and the y value in pixels from the top of the image. The submitted data includes name.x=x-value and name.y=y-value where "name" is the value of the name attribute, and x-value and y-value are the x and y coordinate values, respectively.
地址:
http://www.w3.org/TR/html4/interact/forms.html#h-17.4